Fuel vapors may form in a vehicle's fuel tank when the vehicle is being operated or while the vehicle is parked. Fuel vapors may form in the fuel tank due to an increase in fuel tank temperature. Further, fuel vapors may form due to agitation of fuel in the fuel tank. The fuel vapors may increase pressure in the fuel tank to a level that is higher than desired if the fuel vapors are not allowed to escape from the fuel tank. However, releasing fuel vapors to the atmosphere may not be desirable since releasing the fuel vapors to atmosphere may increase vehicle emissions and decrease vehicle fuel economy. Therefore, fuel vapors may be captured in a carbon filled canister until a time when the fuel vapors may be directed to an engine where they may be combusted to provide torque to the vehicle. However, it may be possible for small amounts of fuel vapors to escape from a fuel vapor storage canister when a vehicle is parked or during other conditions.
The inventors herein have recognized the above-mentioned disadvantages and have developed a method for purging fuel vapors stored in a fuel vapor storage canister, comprising: heating contents of a fuel vapor storage canister via supplying current to a canister vent valve positioned within the fuel vapor storage canister.
By heating contents of a fuel vapor storage canister, it may be possible to provide the technical result of liberating additional fuel vapors from the fuel vapor storage canister so that fewer fuel vapors may be unintentionally released to atmosphere. In particular, heating a fuel vapor storage canister may increase the amount of fuel vapors released from a fuel vapor storage canister during fuel system fuel vapor purging. Further, since the fuel vapor storage canister may be heated via a canister vent valve, the fuel vapor storage canister may be heated without adding components to the fuel system.
The present description may provide several advantages. Specifically, the approach may reduce an amount of fuel vapors that reach the atmosphere. Additionally, the approach may improve increase vehicle fuel economy. Further, the approach may reduce vehicle emissions without increasing vehicle cost.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.